The invention relates to a locking arrangement, in particular for a vehicle to the features of the preamble of patent.
U. S. Pat. No. 5,240,296 discloses a locking arrangement, in particular for a vehicle, an actuator which drives a functional element being provided, in which case various functional positions of the locking arrangement can be set by means of this functional element. These functional positions concern the function xe2x80x9csecured against theftxe2x80x9d, in which a door of the vehicle can be opened neither by the door exterior handle nor by the door interior handle. Further functional positions which may be mentioned are xe2x80x9cunlockedxe2x80x9d and xe2x80x9clockedxe2x80x9d, in which case, in the functional position xe2x80x9cunlockedxe2x80x9d, the door may be opened by both the door exterior handle and the door interior handle, whereas, in the functional position xe2x80x9clockedxe2x80x9d(also called xe2x80x9ccentrally lockedxe2x80x9d), the door may be opened via the door interior handle, so that the occupants of the vehicle may leave the latter, but the door cannot be opened by the door exterior handle, so that access from outside to the vehicle is not possible in this functional position.
The functional element, which in the USA patent is designed as an actuating lever, is moved between various positions by the actuator. A plurality of position-detecting devices, which are designed as potentiometers, are required in order to detect these positions and to control the actuator. The wiper path of the potentiometer are either applied to the inside in the housing of the locking arrangement or are located on a worm gear, which is driven by the actuator. The wipers assigned to the wiper paths sit on the actuating element, the wiper paths being arranged in electric circuits.
It has been found that, although the position-detecting device, which is realized as a potentiometer, works satisfactorily, the construction of the locking arrangement is unsatisfactory, since various parts (functional elements such as worm gear and actuating lever) as well as the housing of the locking arrangement have to be provided with the conductor paths, in which case it is not possible to check the electrical service ability of these elements until after the assembly of the entire locking arrangement. Should it be found at the same time that there are faults in the electrical circuitry or in the position-detecting device, the entire locking arrangement is unserviceable and either cannot be used or requires extensive testing and if need be has to be repaired.
The object of the invention is therefore to provide a locking arrangement described at the beginning, in particular for a vehicle, which locking arrangement is simple to assemble and in which faults in the electrical circuitry or in the position-detecting device do not lead to a failure of the entire locking arrangement. In addition, the position-detecting device is to be easy to exchange.
According to the invention, provision is made for the position-detecting device, in particular a potentiometer, to be formed as a preassembled unit, in which case this unit can be connected to the functional element via connecting means. This has the advantage that the position-detecting device, designed as a preassembled unit, can be electrically tested after its assembly and the serviceability can be established. Only such units which are satisfactory are therefore installed in the locking arrangement. Defective units may be rejected, or may be repaired in order to be subsequently used again.
The ease of assembly is increased owing to the fact that the preassembled unit can be connected to the functional element via connecting means, as a result of which, on the one hand, relative positional orientation between the preassembled unit and the functional element of the locking arrangement is ensured and, on the other hand, tolerances can be compensated for via the connecting means.
Due to the connecting means, it is now also possible, in the event of a mechanical defect of the locking arrangement (for example a defect at the functional element) or in the event of an electrical defect (at the position-detecting device), to exchange the defective component and replace it with a new one. On account of this clearly defined separation of mechanical system and electric/electronic system, it also easy to detect where the fault lies. The correspondingly defective component may then be exchanged quickly and simply.
In a development of the invention, the unit designed as a potentiometer is arranged on a printed circuit board and is held on the printed circuit board by a lock washer. The connection from the position-detecting device to, for example, an analyzing circuit can be made simply and quickly via the printed circuit board, in which case other components may also be arranged on the printed circuit board or may be suitable for connection to the latter. In an especially advantageous manner, the printed circuit board with the potentiometer locked thereto is accommodated in a housing and may thus be oriented in the correct position. The preassembly of the potentiometer on the printed circuit board and the locking with the lock washer has the advantage that the conductor paths on the printed circuit board are held in a fixed position, while the wipers of the potentiometer can rotate about these conductor paths. The use of a linear potentiometer, in which the wipers are moved linearly over the conductor paths on the printed circuit board, is of course not ruled out at this point.
In a development of the invention, the potentiometer and the functional element are arranged on a common shaft. Thus both the mounting for the potentiometer and the functional element as well as the transmission of the movement of the functional element to the potentionmeter by the actuator are combined in the narrowest space, so that a compact type of construction is thereby obtained.
In a development of the invention, a support body of the potentiometer has recesses for accommodating fingers arranged on the functional element, or vice versa. When the support body is being mounted onto the functional element, these fingers engage in the recesses of the functional element (or vice versa), so that, on the one hand, this form grip provides for the force transmission from the functional element to the support body of the potentiometer. This causes the support body of the potentiometer to follow the movements of the functional element and ensures that such an output signal of the potentiometer which represents the position of the functional element is always available. On the other hand, the configuration of fingers/recesses has the advantage that, as a result, there is a defined position and a clearly defined orientation between the support body of the potentiometer and the functional element. This is in particular of importance when the configuration of the recesses and the fingers only permits a single relative position between the support body of the potentiometer and the functional element, so that setting-up work with regard to the position of the support body of the potentiometer relative to the functional element or vice versa may be omitted.
In a development of the invention, the recesses have a smaller depth than the length of the fingers. This means that the fingers cannot engage in their entirety in the recesses, so that there is always a section of the fingers which is not enclosed by the recesses after assembly. This has the advantage that, on account of the geometric construction and possibly depending on the materials used, such as plastic for example, tolerance compensation between the position of the support body of the potentiometer and the functional element is possible. This tolerance compensation occurs on account of slight elasticity of the fingers. In addition, there is also the advantage that temperature fluctuations are compensated for with this geometric construction, a factor which is especially important when said elements are accommodated in a housing of the locking arrangement.
In a development of the invention, the support body of the potentiometer has a bore having a smaller diameter, which is slightly larger than the outside diameter of the shaft. The functional element may thus be mounted on the shaft, whereas the support body is rotatably mounted not on the shaft but on the printed circuit board. As a result, a rigid coupling between the support body of the potentiometer and the functional element is avoided, so that slight movements of the elements are possible in order to be able to compensate for tolerances and possibly also for material expansions and material contractions on account of temperature changes while maintaining the serviceability. Reference is made to the figures for the further configuration of this construction.
In a development of the invention, a coupling defining and securing the relative position between the support body of the potentiometer and the functional element is arranged as connecting means between the support body of the potentiometer and the functional element. This means that the connecting elements have to be arranged not only on the support body and/or the functional element, so that it is conceivable for a coupling to be inserted between the support body and the functional element, which coupling transmits the movement of the functional element to the support body and defines and secures a relative position between the support body and the functional element. Thus, for example, the support body and the functional element may have fingers directed toward one another, while the coupling is provided with correspondingly shaped recesses. With regard to the configuration of such a coupling, reference is also made to the fact that here, too, the recesses may have a smaller depth than the length of the fingers. The advantages described and resulting therefrom apply here in the same manner. Such a coupling may be used, for example, when larger distances have to be bridged between the support body and the functional element.
In a development of the invention, the shaft has a flat, a longitudinal groove, a longitudinal web or the like, which corresponds with a flat, a longitudinal web, a longitudinal groove or the like in the support body of the potentiometer and in the functional element. The relative position between the support body and the functional element is thus also secured in a clearly defined manner, in which case the support body can follow the movements of the functional element here too, and the potentiometer can deliver an output signal representing the position of the functional element.
Features which relate to the assembly of the locking arrangement and which are therefore of advantage with regard to the ease of assembly are provided in the provided.